RFR (M): 8218880: G1 crashes when issuing a periodic GC while the GCLocker is held

[Thomas Schatzl]

Hi,

  thanks for your review.

On Wed, 2019-02-27 at 11:50 +0100, Aleksey Shipilev wrote:
> On 2/27/19 10:29 AM, Thomas Schatzl wrote:
> > CR:
> > https://bugs.openjdk.java.net/browse/JDK-8218880
> > Webrev:
> > http://cr.openjdk.java.net/~tschatzl/8218880/webrev/
> 
> Nits:
> 
> *) "pause_succeeded" is a confusing name. "vmop_succeeded" adds to
> confusion. Maybe both locals and
> the methods should be called "gc_succeeded"?
> 
> 2151       vmop_succeeded = op.pause_succeeded();

Fixed by using "gc" everywhere (I hope).

> 
> 
> *) I think burning here without backoff is not nice for the test,
> maybe sleep a little?
> 
> libTestPeriodicCollectionJNI.c:
>   40     while (!release_critical) /* empty */;
> 
> 

I have been hesitant to go this way because of the many platforms we
support, however it seems enough to just special-case Windows.

I also added and extern "C" declaration to the test like many (but not
all) other similar JNI code.

New webrevs:
http://cr.openjdk.java.net/~tschatzl/8218880/webrev.0_to_1/ (diff)
http://cr.openjdk.java.net/~tschatzl/8218880/webrev.1/ (full)

Test passes on all Oracle platforms.

Thanks,
  Thomas